Millions of cans of beverages, such as soft drinks and beer, are sold every day. The vast majority of these cans now include an end closing structure which includes an easy-opening feature thereon.
Such easy-opening can end features are formed in can ends by such metal working operations as drawing and scoring. Careful control of such operations is essential, since close tolerances must be maintained in order that the cans both open properly without excessive effort on the part of the consumer yet do not leak under the internal pressure of the carbonated beverage therewithin.
In order to regularly check on the quality of can ends being produced, it is common practice to test several ends produced from a can end line for every packaged sleeve of ends produced. A sleeve of ends typically contains in the order of 408 or so ends. Such testing requires that the test ends be removed from the packaging line, stored until sufficient ends for testing are collected, transporting the collected ends to a remote testing station and testing these ends on previously-known can end pressure testers. Typical of the prior-known can end testers is a Borden Model 180-B-80 tester. Such a tester forms a pocket around the end, with compressed air being forced onto the end from one side and a test for leakage of this air through the other side.
Because of the delay in testing of finished ends, it is possible for many defective ends to be produced subsequent to a defect initially occurring. Thus, it has become the practice to hold a completed pallet of can ends prior to their release for shipment until testing of the sample ends has been completed. Should a single test end fail the pressure test, current practices call for all subsequent ends produced from the line in which the defect occurred to be individually tested prior to release of any of these ends. Such a procedure is obviously time consuming and expensive of itself, as well as expensive in potentially scrapped ends which will be produced between the time the defect first appeared and the time where the defect became known.
It would be desirable, therefore, to produce an apparatus which could be integral with the can end line and which routinely tests sample ends from production substantially in real time with their production. Such an apparatus would be substantially smaller than the pressure testers commercially available, since the required capacity for such a unit will be far less than that of those currently employed. At the same time, production costs could be substantially decreased by catching and correcting a defect substantially immediately after its occurrence, thus substantially reducing the number of potentially defective ends produced after the initial defect has occurred, resulting in reduced scrap, as well as labor costs, involved in producing and testing potentially defective ends.